Publications associées à Rayonnement sortant à grande longueur d'onde

Intermediate complexity atmospheric modeling in complex terrain: is it right?

Michael Lehning, Dylan Stewart Reynolds, Michael Haugeneder

Dynamic downscaling of atmospheric forcing data to the hectometer resolution has shown increases in accuracy for landsurface models, but at great computational cost. Here we present a validation of a novel intermediate complexity atmospheric model, HICAR, ...

Frontiers Media Sa2024

On the importance of the humidity flux for the surface mass balance in the accumulation zone of the Greenland Ice Sheet

Sonja Wahl

It is highly uncertain how the humidity flux between the snow surface and the atmosphere contributes to the surface mass balance (SMB) of the interior Greenland Ice Sheet (GrIS). Due to sparse observations, evaluations of the simulated humidity flux are li ...

Copernicus Gesellschaft Mbh2024

Resolving indoor shortwave and longwave human body irradiance variations for mean radiant temperature and local thermal comfort

Dolaana Khovalyg, Arnab Chatterjee, Mohamad Rida

A spatially and directionally resolved longwave and shortwave radiant heat transfer model is presented via a series of experiments in a thermal lab to input surface temperatures and geometries, as well as skin temperature readings from a human subject, in ...

2023

Evaluation of 30 urban land surface models in the Urban-PLUMBER project: Phase 1 results

Gabriele Manoli, Matthias Roth

Accurately predicting weather and climate in cities is critical for safeguarding human health and strengthening urban resilience. Multimodel evaluations can lead to model improvements; however, there have been no major intercomparisons of urban-focussed la ...

Wiley2023

Arctic warming by abundant fine sea salt aerosols from blowing snow

Julia Schmale, Nora Bergner, Jian Wang, Xin Yang, Markus Frey

The Arctic warms nearly four times faster than the global average, and aerosols play an increasingly important role in Arctic climate change. In the Arctic, sea salt is a major aerosol component in terms of mass concentration during winter and spring. Howe ...

2023

Assessment of the Thermal-Hydraulic Performance of the European DEMO NbTi Bus Bars

Rainer Wesche, Kamil Sedlák, Roberto Guarino

We present a numerical assessment of the thermal-hydraulic performance of the NbTi bus bars designed for the European DEMO. We consider the CS, TF and PF bus bars, as well as two alternative TF options for high-current operations. The main sources of stati ...

IEEE Institute of Electrical and Electronics Engineers2022

Black carbon and dust in the Third Pole glaciers: revaluated concentrations, mass absorption cross-sections and contributions to glacier ablation

Julia Schmale, Yang Li, Xinyang Li

In snow and ice, light-absorbing particles (LAPs), such as black carbon (BC) and dust, accelerate the melting of Third Pole glaciers (TPGs). In this study, we revaluated LAP concentrations in the snow pits of TPGs (SP-TPGs), measured LAP mass absorption cr ...

2021

Modeling Extreme Warm-Air Advection in the Arctic During Summer: The Effect of Mid-Latitude Pollution Inflow on Cloud Properties

Georgia Sotiropoulou

Usually the Arctic is relatively free of anthropogenic influence in summer, which means that particles from natural sources can be the most significant nuclei for cloud droplets. However, this is not the case during anomalously warm-air intrusions when the ...

2021

Numerical characterization and engineering of transport in morphologically complex heterogeneous media

Xiaoyu Dai

A multi-scale numerical methodology for the assessment of radiation and optical characteristics of complex structured soot-contaminated snow layers was investigated first. The methodology accounted for the exact morphology at the various scales and utilize ...

EPFL2021

Disruption mitigation efficiency and scaling with thermal energy fraction on ASDEX Upgrade

Basil Duval, Umar Sheikh, Gergely Papp

Disruption mitigation remains a critical and unresolved issue for ITER. Measurement uncertainties preventing quantification of a system's efficacy remains a significant hurdle in producing and validating a viable disruption mitigation system. This study ad ...

IOP Publishing Ltd2020

Correction of CCI cloud data over the Swiss Alps using ground-based radiation measurements

Alexis Berne, Fanny Alexia Jeanneret

The validation of long-term cloud data sets retrieved from satellites is challenging due to their worldwide coverage going back as far as the 1980s. A trustworthy reference cannot be found easily at every location and every time. Mountainous regions presen ...

Copernicus GmbH2018

Investigation of snow melt dynamics and boundary layer processes over a melting snow surface

Sebastian Schlögl

In this thesis, we investigate the surface energy balance of a snow pack for a continuous and a patchy snow cover. Snow surface temperatures have been validated to assess the accuracy of the surface energy balance of a continuous snow pack for individual p ...

EPFL2018

Improving surface heat flux estimation for a large lake through model optimization and two-point calibration: The case of Lake Geneva

David Andrew Barry, Ulrich Lemmin, Damien Bouffard, Andrea Cimatoribus, Abolfazl Irani Rahaghi

Net Surface Heat Flux (SurHF) was estimated from 2008 to 2014 for Lake Geneva (Switzerland/France), using long‐term temperature depth profiles at two locations, hourly maps of reanalysis meteorological data from a numerical weather model and lake surface w ...

Association for the Sciences of Limnology and Oceanography (ASLO)2018

Large-scale and meso-scale surface heat flux patterns of Lake Geneva

Abolfazl Irani Rahaghi

Diverse studies have confirmed the adverse impact of global climate change in lakes. In order to establish effective water quality management policies, it is essential to understand how the heat exchange between the atmosphere and the lake evolves under th ...

EPFL2018

Optical characterization of multi-scale morphologically complex heterogeneous media – Application to snow with soot impurities

Sophia Haussener, Xiaoyu Dai

A multi-scale methodology for the radiative transfer analysis of heterogeneous media composed of morphologically-complex components on two distinct scales is presented. The methodology incorporates the exact morphology at the various scales and utilizes vo ...

Elsevier2018

Measurement of the impact of buildings on meteorological variables

Jean-Louis Scartezzini, Dasaraden Mauree, Laurent Deschamps, Pierre Loesch, Paul Becquelin

A meteorological tower was installed on the EPFL campus in a semi-urban environment for the high frequency monitoring of the micro-climate. This project was done in the larger framework of the measurement of the meteorological profiles and also a quantific ...

2017

Tomography-based radiative characterisation of decomposing carbonaceous heat shield materials

Sophia Haussener, Pénélope Leyland, Nikhil Banerji

This work evaluates the changes in radiative properties of two decomposing carbonaceous porous materials, each composed of two semitransparent, homogeneous and isotropic phases. The understanding of the complex dependence of macroscopic optical behaviour o ...

Pergamon-Elsevier Science Ltd2017

High-flux optical systems for solar thermochemistry

Sophia Haussener, Gaël Jean Clément Levêque

High-flux optical systems (HFOSs) are optical concentrators used to increase the radiative flux of the natural terrestrial solar irradiation. High radiative flux concentration leads to high energy density in solar receivers which allow to obtain high tempe ...

2017

Negative elevation-dependent warming trend in the Eastern Alps

Mountain regions and the important ecosystem services they provide are considered to be very vulnerable to the current warming, and recent studies suggest that high-mountain environments experience more rapid changes in temperature than environments at low ...

Iop Publishing Ltd2016

Spatial estimates of snow water equivalent from reconstruction

Annelen Kahl

Operational ground-based measurements of snow water equivalent (SWE) do not adequately explain spatial variability in mountainous terrain. To address this problem, we combine satellite-based retrievals of fractional snow cover for the period 2000 to 2011 w ...

Elsevier2016